Diff Checker
Compare two blocks of text and instantly see every difference highlighted. Line, word, and character diff modes with options to ignore whitespace, case, and blank lines. Free. No sign-up.
Paste text in both panels and click Compare to see differences.
How it works
- 1Paste your texts
Paste the original text on the left and the modified version on the right. You can also type directly.
- 2Choose diff mode
Select line, word, or character diff. Toggle options to ignore whitespace, case, or blank lines.
- 3Review and export
Scroll through highlighted differences, jump between changes, and copy or download the diff output.
Why You Need a Diff Checker
Comparing text is a fundamental task in software development, content writing, and document management. Whether you are reviewing code changes before a commit, checking edits on a legal contract, or verifying that a configuration file was updated correctly, a diff checker saves you from the error-prone process of reading two documents side by side and trying to spot every difference manually.
Our diff tool implements a Longest Common Subsequence (LCS) algorithm to produce accurate, minimal diffs. It first compares text line by line to identify added, removed, and unchanged lines. For changed sections, it drills down to the word or character level, highlighting exactly what changed within each line. This two-level approach gives you both the big picture and the fine detail.
The ignore options let you filter out noise. Whitespace differences are common when reformatting code or pasting from different editors. Case differences matter in some contexts but not others. Blank line changes are often irrelevant when reviewing content edits. By toggling these options, you can focus on the changes that actually matter.
The jump navigation lets you move between changes quickly, even in long documents with thousands of lines. The diff statistics give you an at-a-glance summary of how much changed. And when you need to share or archive the comparison, you can copy the diff to your clipboard or download it as a text file.
All processing happens entirely in your browser. Your text never leaves your device, making this tool safe for source code, credentials, private documents, and any other sensitive content you need to compare.